Line 13x9-inch pan with foil, with ends of foil extending over sides. Spray with cooking spray. Mix graham crumbs, 1/2 cup nuts and butter; press onto bottom of pan.
Beat cream cheese and sugar in large bowl with mixer until well blended. Add sour cream and vanilla; mix well. Add eggs, 1 at a time, mixing on low speed after each just until blended. Pour over crust.
Bake 45 minutes or until centre is almost set. Cool completely. Refrigerate 4 hours. Drizzle with caramel topping; sprinkle with remaining nuts. Use foil handles to lift dessert from pan before cutting into bars.